package com.atguigu.gulimall.product.service.impl;

import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;

@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page =
            this.page(new Query<CategoryEntity>().getPage(params), new QueryWrapper<CategoryEntity>());

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        // 1.查出所有分类
        List<CategoryEntity> entities = baseMapper.selectList(null);
        // 2.组装成父子的树形结构
        // 2.1找到所有的一级分类
        List<CategoryEntity> levelOneMenus =
            entities.stream().filter(categoryEntity -> categoryEntity.getParentCid() == 0).map((menu) -> {
                menu.setChildren(getChildren(menu, entities));
                return menu;
            }).sorted((menu1, menu2) -> {
                return (menu1.getSort() == null ? 0 : menu1.getSort())
                    - (menu2.getSort() == null ? 0 : menu2.getSort());
            }).collect(Collectors.toList());
        return levelOneMenus;
    }

    private List<CategoryEntity> getChildren(CategoryEntity root, List<CategoryEntity> all) {
        List<CategoryEntity> collect = all.stream().filter((categoryEntity) -> {
            return categoryEntity.getParentCid() == root.getCatId();
        }).map(categoryEntity -> {
            categoryEntity.setChildren(getChildren(categoryEntity, all));
            return categoryEntity;
        }).sorted((menu1, menu2) -> {
            return (menu1.getSort() == null ? 0 : menu1.getSort()) - (menu2.getSort() == null ? 0 : menu2.getSort());
        }).collect(Collectors.toList());
        return collect;
    }

}